Front head for pneumatic tools



,1. H. J'OWETT "Filed Dec. 12, 1929 I N VEN TOR. Tau/afil v N g FRONTHEAD FOR PNEUMATIC TOOLS Patented Dec. 9, 1930 TUNITED STATES JAMES H.JOWETT,0F NEW YORK,

N. Y., ASSIGNOR '10 INGERSOLL-RAND COMPANY,

or J'EBSEYCITY, NEW JERSEY, A conronarron or NEW JERSEY rnon'r HEAD on.PNEUMATIC roots Application: filed December 12, 1929. Serial No.413,517.

This invention relates to pneumatic tools, but more particularly to afront head for pneumatic tools of the hammer type.

One object of theinvention is to protect the working implement againstthe strains 11101 dent to prying portions of the work free from themass.

Other objects will be in part obvious in part pointed out hereinafter.

In the drawings'illustrating the invention and in which similarreference characters refer to similar parts, I V

Figure 1 is a longitudinal view partly in section of a pneumatic toolconstructed in accordance with the practice of theinvention,

Figure 2 is a longitudinal side view of the front head, and

Figure 3 is a transverse view taken through Figure 1 on the line 3-3looking in the direction indicated by the arrows.

Referring more particularly to the drawing's, A designates generally apneumatic tool comprisin a cylinder B having a piston chamber wherein isdisposed a reciprocatory hammer piston D.

The pressure fluid utilized for actuating the piston D may bedistributed to the extremities of the piston chamber by suitable valvemechanism (not shown) and such pressure fluid may be conveyed to thepiston chamber through the usual channels, only the front inlet passageE of which is shown.

At the front end of the cylinder B is a reduced portion F having a boreG to slidably receive the shank H of a working implement J. The workingimplement J is illustrated as being of the coal pick type andaccordingly has a coniform cutting bit K at its front or free end. Atthe juncture of the body portion and,

of the working implement and the shank H is a collar L which is adaptedto abut the front end of the portion F to limit the distance which theshank H of the working implement may extend into the piston chamber C.

Additional means are provided for properly guiding the working implementJ as well as for preventing it from being forcibly ejected from thecylinder A. To this end a front head 0 is threaded to the portion Fenlarged portion Q of the bore P.

and said front head has a hore therein to slidably receive the bodyportion of the working implement J. The rearendof the bore P is enlargedas at Q to accommodate the collar L of the working implement. Theenlarged portion Q of the bore. is pref=: erably of such length that thecollar L is capableof considerable movement longitudinally of'the fronthead without contacting with the elements which may serve as stopstherefor, such as the front endrof the or; tion F and, as illustrated,stop pins R w ich extend laterally through the front end of theTheapertures S wherein the pins R are disposed preferably extendentirely through the ront head 0,.and the pins R areretain'ed within theapertures S by a spring-ring T which liesiu an annular groove U in theperiphery of the front head. 1

In order to insure against the unthreading of the front head 0 from theportion Q, of the cylinder, the rear endof the front head is providedwith a longitudinal slot V and a bolt W cxtendsjthrough the side of thefront head adjacent the slot V and is provided with a nut X whereby therear end of the front head may be securely clamped to the cylinder. 7: vPneumatic tools of the type to, which the present invention pertains aremoreparticuarly adaptedfor use in mining coal and similar work in whichportions of the material are broken from the bed or mass by bothdrilling and prying. f a V The usual procedure is to actuate the workingimplement into the work by means of the hammer piston D. Aftertheworking implement has penetrated the work' to a certain extent, orwhen there is evidence of portions of the rock being fractured, thetool, together with the working implement, is used as a pry fordisplacing the partly broken material.

The present invention contemplates the use of a portion of a casingelement as a means for both severing the material and also as a pryingelement which may serve the additional function of protecting therelatively yieldable working implement against the strains incident toprying. In furtherance of this end the front head O is, provided withtapering surfaces Y which are preferably flat and have their point ofconvergence at the front end of the front head to form a. wedge orcleaver portion Z having cutting edges 12 at its front end. The cuttingedges are preferably arranged on diametrically opposite sides of theworking implement and are perpendicular to the longitudinal axis of saidworking implement.

The surfaces Y may be of any suitable degree of inclination and thecutting edges of the cleaver portion Z are preferably in such proximityto the cutting bit K of the working implement that the edges Z) mayclosely follow the cutting bit K into the work. Due to this arrangementthe working implement will be actuated into the work by the direct blowof the hammer piston D and the cleaver portion Z of the front head willbe caused to enterthe line of cut by the jars resulting from thecompression created by the piston as it approaches the front end of thepiston chamber C.

' After the working implement and the cleaver portion Z have penetratedthe work to an extent to which they may be readily actuated by thehammer piston, manual pressure may be applied in a lateral direction tothe rear end of the tool and in this way the portion of the workintended to be severed may be readily broken free from the mass. Anystrains to the drilling apparatus occasioned by this prying action willbe largely confined to the relatively rugged and inflexible front head 0instead of to the working implement as heretofore.

I claim:

1. A pneumatic tool comprising a casing, a Working implement guidedthereby, a hammer piston to actuate the working implement, andconverging surfaces on the casing forming a cleaver portion adapted toenter the work for breaking portions thereof free from the mass.

2. A pneumatic tool, comprising a casing,

a working implement guided thereby, a hammer piston, to actuate theworking implement, and surfaces on the casing converging toward one endthereof to form a cleaver portion adapted to enter the work for breakingportions thereof free from the mass.

3. A pneumatic tool, comprising a casing, a working implement guidedthereby, a hammer piston to actuate the working implement and a wedgeportion integral with the casing and adapted to enter the work forbreaking portions thereof free from the mass.

4. A pneumatic tool comprising a percussive element, and a casing havinga cleaver portion adapted to be actuated into the work by the percussiveelement to break portions of the work free from the mass.

5.. A pneumatic tool comprising a casing, a. working implement guidedthereby, a hammer piston to actuate the working implement, and a wedgeportion integral with the casing and having cutting edges on oppositesides of the working implement.

6. A pneumatic tool comprising a casing, a working implement guidedthereby, a hammer piston. to actuate the working implement, and a wedgeportion integral with the casing and having. cutting edges ondiametrically opposite sides of the working implement.

7. A pneumatic tool comprising a casing, a working implement guidedthereby, a hammer piston to actuate the working implement, and a Wedgeportion integral with the casing and having cutting edges ondiametrically opposite sides of the working implement and arrangedperpendicularly with respect thereto.

In testimony whereof I have signed this specification.

JAMES H. J OWVETT'.

